Font Size: a A A Safety Assessment And Remaining Life Estimation Of Coke Drums Posted on: 2006-06-06 Degree: Master Type: Th esi s Country: China Candidate: J Y ou Full Text:PDF GTID:2121360242985109 Subject: Power Machinery and Engineering Ab st rac t/Su mmary: Order a copy of this th esis Coke drumis th e key device of delayed coking in pet rochemical indu stry , and due to its long exp osure to the severe s ervice environm ent th e temp erature of which changes form room t em perature to 480℃cyclically and the effect of cyclic loading, it is easy to raise some kinds of failure relating to structural strength, which may lead to unexpected grave accident, so it is necessary to do a rounded structural analysis and estimate the remaining life of coke drum.For the accuracy of the remaining life estimation, the structural analysis of coke drum in service conditions has been carried out, and the stages of coke generating and water cooling were emphasized on, in which the coke drum experiences the largest temperature change. Based on the FEM theory, the transient heat transfer between the drum wall and fluid medium rising up with steady rate was simulated numerically first, then the time history of the stress and strain fields were acquired with indirect coupling method. The results indicate that the outboard of drum wall falls in plastic yielding in the water cooling stage and the welded seam is under multiaxial stress state.Thermal mechanical fatigue (TMF) under multiaxial state, the fundamentals of which have not been studied well, is one of the most complex parts in the fatigue study. In this paper, notched specimens made of material taken from coke drum in service were used to carry out in-phase TMF test and crack propagation test, then the commercial FEA software ANSYS was employed to acquire the stress and strain history of the specimen in a cycle of loads. Based on the numerical results, the local stress-strain method was employed to establish the life estimation equations which use the equivalent plastic strain and equivalen t plastic strain energy d ensity as th e governing paramet ers. By app lying t he em pirical equations, the remaining life of the inv estigat ed coke drum is figured out as approxim ately 24 years.The crack propagation under multiaxial stress state has also been studied in this paper. The opening and closing p rocess of crack in a cycle of loads has been simul ated successfull y w ith the use of rigid -soft contact pair in ANSYS, and th e J -int egral w as calculat ed on th e local crack t ip of the finite elem ent m odel directly , then t he range of the J -integral in a cycle of loads w as em ployed as th e key paramet er describing th e crack propagation regularity. The empirical equation is expected to be helpful to estimate the fatigue crack propagation life of the coke drum. Keywords/Search Tags: Coke Drum, FEM, TMF, Crack Propagation Life , J-integral Related items 1 Research On A Criterion For Crack Propagation Based On The Radial Strain Energy At Plastic Core Region An d Numerical Simul ation 2 Workin g Process Nume rical Simulation And Li fe Evaluation Of Coke Drum 3 Studies On Coke Coolin g Process I n Coke Drum 4 Study On The Endurance Strength A nd Residual Li fe Estimation Of The Material In Coke Drum's Body 5 Study On Physical Properties Of Low Carbon Steel 20g And The Deformation Mechanism Of Coke Drum 6 The Work Process And I mitating Analysis Of Coke Drum 7 The Study On Fatigu e Crack Growt h Of High Strength Steel 8 Simulation Research On Crack Propagation Of Solid Material 9 The Study Of Mechanism Of Crack Propagation Of LaPO 4 Coated Al 2 O 3 Methinable Ceramics 10 The Study Of Mechanism Of Crack Propagation Of Lapo 4 Coated Al 2 o 3 Methinable Ceramics Globe Thesis Copyright ©2013. All Rights Reserved. | Privacy | Copyright | Contribute | Ab ou t | Contact | RSS Type here to search on Globethesis.com S a fe ty As s e s s men t An d Re ma in in g Life Es t im at io n O f Co k e Drums h t tp :/ /w ww .g lo b e t h e s is .com /? t = 2 1 2 1 3 6 0 2 4 2 9 8 5 1 0 1 o f 1 1 2 - 0 4- 2 0 1 3 1 3 : 0
